Explorations of Oxygen-Free Seas on the Oceanus (Part II: Clemens and Claudia)

Six thousand feet below our ship, three tectonic plates are colliding. Like slow-moving conveyor belts, the Rivera and Cocos Plates creep under the North American Plate. Where the denser oceanic plates dip below the less dense continental crust, the Middle America Trench is formed.

Tectonic plates move extremely slowly, at about the same rate your fingernails grow. But in a few million years, the marine mud riding east towards America on the oceanic crust will reach a fiery fate as fodder for future Mexican volcanoes.

To sample these sediments, a special coring device hooked to a cable on the ship is lowered to the ocean floor, thousands of feet below. Then the wire is carefully rewound to bring the plastic sleeves filled with mud cores to the surface.

In such deep waters, this coring process can take hours, and there’s no guarantee of success; about half the time, the core hits hard rock instead of soft sediment, or the mud escapes from the tubes before the scientists can recover it. Despite the odds, we have already recovered sediments from three stations, in depths up to three thousand meters of water.

Sediment bacteria experience big metabolic shifts due to temperature and pressure changes during the journey from their native habitat to the sea surface. Clemens Schauberger, a PhD student in Professor Bo Thamdrup’s lab at University of Southern Denmark, wants to freeze a snapshot of these sediments in time to study their complex microbial communities. Schauberger is testing how to stabilize nucleic acids on the seafloor before their long voyage to the surface.

Claudia Remes, a Masters student in Alejandra Prieto-Davo’s lab at the National Autonomous University of Mexico, is saving some of these sediments from imminent tectonic destruction, in the hopes that they can help humans fight infectious pathogens. Almost all of known antibiotics come from land; Remes and Prieto-Davo are working to uncover new natural microbial products from the deep sea.

As a former gamer, Remes likes to compare science to a videogame: she thinks of each station as a new level in her quest. After retrieving the core, she dries the mud in petri dishes, grinds it, and stamps the powder onto agar gel designed to select for Actinobacteria with specialized enzymes that make antibiotics. Her favorite pet bacterium in the lab is a chubby pink one she named “Kirby” after the Nintendo character.

Stay tuned for more blog posts over the next ten days of our expedition. In each, I will feature scientists from the expedition and the exciting research that inspires them to go to sea.